Data_Sheet_1_In situ Generated Ru(0)-HRO@Na-β From Hydrous Ruthenium Oxide (HRO)/Na-β: An Energy-Efficient Catalyst for Selective Hydrogenation of Sugars.DOCX

A green process for the hydrogenation of sugars to sugar alcohols was designed in aqueous medium using hydrous ruthenium oxide (HRO) as a pre-catalyst supported on Na-β zeolite. Under optimized reaction conditions, sugars such as xylose, glucose, and mannose converted completely to the corresponding sugar alcohols xylitol, sorbitol, and mannitol with 100% selectivity. The pre-catalyst (HRO) is converted in situ to active Ru(0) species during the reaction under H2, which is responsible for the hydrogenation. The catalyst was recyclable up to five cycles with no loss in activity. The reduction of HRO to the active Ru(0) species is dependent on the reaction temperature and H2 pressure. Ru(0) formation increased and consequently an increased hydrogenation of sugars was observed with an increase in reaction temperature and hydrogen pressure. Further, in situ generation of Ru(0) from HRO was assessed in different solvents such as water, methanol, and tetrahydrofuran; aqueous medium was found to be the most efficient in reducing HRO. This work further demonstrates the use of supported HRO as an efficient pre-catalyst for biomass-based hydrogenation reactions.本研究设计了一种以Na-β沸石（Na-β zeolite）负载的含水氧化钌（hydrous ruthenium oxide，HRO）作为预催化剂的绿色工艺，可在水相介质中实现糖类加氢制备糖醇。在优化后的反应条件下，木糖、葡萄糖、甘露糖等糖类可完全转化为对应的木糖醇、山梨醇、甘露醇，且选择性达100%。该预催化剂（HRO）在氢气氛围下的反应过程中可原位转化为活性金属钌(0)物种，该物种为糖类加氢反应的活性中心。该催化剂可循环使用至多5个周期且活性无衰减。含水氧化钌还原为活性Ru(0)物种的过程受反应温度与氢气压力调控：随着反应温度和氢气压力升高，Ru(0)的生成量增加，糖类的加氢转化效率也同步提升。此外，本研究还考察了HRO在水、甲醇、四氢呋喃等不同溶剂中原位生成Ru(0)的效果，结果表明水相介质对HRO的还原效能最为优异。本工作进一步证实，负载型HRO可作为高效预催化剂应用于生物质基加氢反应。